.450 in a bolt gun

[Marlin Junky]

Does anyone have a .450 Marlin bolt gun? I've been thinking about re-barreling a short action M77 (2.9" mag. box) to .450 Marlin but wondering if the extra magazine length is worthwhile give the currently available mold designs from RCBS, SAECO and Lyman. Also wondering if (even with a 20" twist) I'd really gain an advantage in velocity since most cast bullet success (at least for me) has been at under 40K PSI (estimated pressure from QuickLoad).

MJ

[beagle]

No, but I have a .458 X 2" and it's basically the same and would probably be the way to go as magnum brass is readily available and opposed to .450 Marlin brass.

The only problem I have is that much of the available powder space is taken up by the bullet. Still, I get about all of the velocity out of it that I want....especially with 500 grain+ bullets.

Mine has a 1:20 twist Douglas on a M1903A3 high numbered Springfield and the accuracy is there so that twist is the way to go.

In my opinion, it's only a belted .45/70./beagle

[Marlin Junky]

In my opinion, it's only a belted .45/70./beagle

Beagle,

That's correct, but it will work in a M77 action. Can you tell me about your full house 400 to 450 grain loads... like what kind of powder, velocity, accuracy, etc.? I'm wondering if I should just get a .458WM barrel and deal with the 2.9" magazine box because I'll probably never want to shoot anything above 400 to 425 grains.

Thanks,
MJ

[NHlever]

Brockman makes a .450 Marlin bolt gun, but it is pricy. The .450 should work with any magnum bolt face in a Ruger, but the feed rails might be an issue. I'm sure you could get a .458 Mag magazine box from them, but some of the .458's didn't feed as well as they might. The new controlled round actions might be a lot better in that regard.

[Larry Gibson]

Beagle,

That's correct, but it will work in a M77 action. Can you tell me about your full house 400 to 450 grain loads... like what kind of powder, velocity, accuracy, etc.? I'm wondering if I should just get a .458WM barrel and deal with the 2.9" magazine box because I'll probably never want to shoot anything above 400 to 425 grains.

Thanks,
MJ

I've a Siamese Mauser 45-70 that I load right on up there. I also test pressure with it using the M43 Oehler. I can give you some kind of load and pressure info if you are interested up through a load for the 400 gr Barnes SO (O) at 2250 fps . Also the 2.9" mag length is plenty, even for use with 500+ gr. I've often though the .450 Marlin on a medium length magnum action would be a nice equivelent.

Larry Gibson

[Marlin Junky]

Larry,

A 400 grain bullet at 2250 fps sounds like it'll generate too much pressure for accurate shooting with cast; i.e., PSI will be way over 40K. Is this correct? Actually the .450 Marlin would generate even more pressure than a 45-70 at the same velocity and with the same powder because of reduced case capacity.

I just checked prices on .450 brass and it is actually more expense than .458WM brass.

MJ

[Larry Gibson]

Marlin Junky

A 400 grain bullet at 2250 fps sounds like it'll generate too much pressure for accurate shooting with cast; i.e., PSI will be way over 40K. Is this correct? Actually the .450 Marlin would generate even more pressure than a 45-70 at the same velocity and with the same powder because of reduced case capacity.

Oh yes, a 400 gr at 2250 will mucho much pressure way over 40,000 psi! However that was with a Barnes jacketed bullet and it's pressures were about max for the Mauser and would be close to max for your Ruger. I have pushed the 458483 ( a 400 gr GC bullet) to 2050 fps but have not pressure tested it yet. Nor have I pressure tested the Lee 500 gr GC bullet at 2000 fps. Those are on my "to do" list. Just waiting until I feel like bench shooting them for the Joe Forman right hook feeling! My rifle weighs in at 8.5 lbs and the recoil is up into the 45-50 ftlbs with those loads.

I just checked prices on .450 brass and it is actually more expense than .458WM brass.

Well, if you want to dance sometimes you got to pay the band! I get away with neck sizing my cases and they have lasted 30 years and many, many firings.

Larry Gibson

[looseprojectile]

what I thought was a 45 70 in a Siamese Mauser. Turned out to be a 450 Alaskan.
Surprise, holds more powder than a 450 Win. Mag. Long heavy rifle.
Too much gun for me. Does dang well with reasonable loads.
The 45 70 makes more sense.
With boolits a 45 70 is plenty good enough!
Custom rifles are expensive nowadays. If I didn't have two 45 caliber rifles I think I would go with a Lee Enfield conversion in 45 70.
Just my opinion.

Life is good

[Bull Shoals]

I had a 458x2" built several years ago. Load used was 49 grains of 4198, Win LR primer and Speer 400 gr SP. Vel was right at 2000 fps. All I wanted in a 9 # rifle.

[StrawHat]

I had a 458x2" built on a Remington 722 action. Nice light rifle that handled recoil well because of stock design or maybe because I was in my 20 and 30s when I had it.

Don't see why the 450 Marlin would not work in a bolt gun. Advantage with the 450 is the headstamp would match the rifle.

It is possible to slip a 458x2" into a 300 Winchester Magnum and others, I doubt it would swage down!

[beagle]

I haven't worked with mine that much as I was caught up in my move just as I got it completed. I've used mostly .45/70 loads as they're about all that I need. I had it made and throated using a dummy loaded with a Lyman 462560 bullet and it plops those right in there.

In initial testing, I have noticed that powder capacity is limited by the bullet. I haven't even began to develop any elephant loads for it but that may come in the spring.

They're fun guns but I still think the advantage goes with using a belted magum case as opposed to the .450 case with the oddball/longer belt.

I did neck ream these that I made from magnum cases (mostly 7MM Mags and .338s Mags) and that seems to give a better case mouth seal and better accuracy./beagle

[Marlin Junky]

Beagle,

What about shortening the .458WM cases to about 2.25"?

Would that require an expensive custom reamer or just a fancy gunsmithing trick to make a .458-2.25" work?

MJ

[beagle]

You can shorten .458 Win Mag cases but that's kind of a waste being as .458 brass is so expensive. You still run into thicker case walls with the .458 stuff as it's thicker as you move toward the base. I normally take about any belted mag case range pickup, cut with a tubing cutter, trim to length, expand and then ream with a Forster trimmer.

Now, here's another glitch. The normal cutting heads on a Forster trimmer are too small to reliably cut the stuff back so I use an old Lyman trimmer checked to an electric drill. Man, the brass shavings fly.

I was using unreamed brass but I was getting smoking around the necks and after talking with another member here that had a .458 X 2, we reached the conclusion that the necks were too thick. I had difficulty with seating before reaming as well. After reaming to bullet seating depth, the seating was easier and the smoke around the case mouth almost disappeared.

It's a lot of fun to mess with and the brass is almost indestructable./beagle

[Marlin Junky]

I think I'll just buy a Marlin in 45-70.

MJ

[leadeye]

The solution to any problem, buy another Marlin. Works for me! I love that mix of the laminated stocks and the stainless steel.

[NHlever]

I've talked to some folks I know at Ruger about chambering the Alaskan MKII in .450 Marlin since they have all the components that they would need to do that, but so far I haven't gotten much response. I'd like to see it in that new short mag rifle configuration with the walnut stock and 20" barrel. Wouldn't hurt to mention it to them if it sounds interesting.

[Bass Ackward]

I have a 458X2 and have had at least one since the mid 70s. While brass can come cheap, dies are expensive now. I think that the set-up I have would cost over $400 today to replace. And I have brass that I have been using since the 70s. In fact, I can't remember having one go bad.

So cost advantage in one area for of one caliber can be used up in another area. You can get creative on dies to cut costs, but concentricity can still suffer if you are not careful.

In truth, shooting any 45 caliber today is not cheap and it is going to be more expensive tomorrow.

As far as cast goes, best accuracy in all guns, 14 - 22 twist has always been in the 1300 fps and 2100 fps area. Secret is not to cut too short of a barrel for the top end stuff.

[threett1]

I have a Siamese Mauser action that has been hanging in the shop for just about forever. Think it would make a good 450 Marlin? I realize 45/70s are built on them, but I wanted something different for this one.

[dk17hmr]

If you want to try out a 450 Marlin, why not look for a NEF in 450 Marlin.

I have one, with a Nikon 2-7 shotgun scope one it will throw 325gr Hammer bullets at 2300fps into 1.75" or smaller at 100 yards. Its not much fun to shoot from the bench though.